This invention relates to an electrically programmed shutter assembly, and more particularly to a shutter assembly including an opening ring and a closing ring wherein the closing ring is prevented from closing the shutter blades prior to attainment of a minimal lens opening.
The shutter blades of programmed shutters overlap a predetermined amount when a locked positioned. Thus, there is a time interval from the start of the opening movement of the shutter blades by rotation of the opening ring until a minimal lens opening occurs. In electrically programmed shutter assemblies, under intensive lighting conditions, the situation can arise that no light will pass through the shutter, dispite having released the shutter button. This may occur, when the camera is utilized in intensive illumination and the holding magnet retaining the closing ring releases the closing ring as soon as the opening ring has started to move. In these cases, the user will not be aware that he has missed a shot so that loss of exposure is doublely annoying.
Accordingly, it would be desirable to provide a programmed shutter of the conventional type wherein it is possible to insure that a predetermined minimal opening of the shutter blades occurs, independent of illumination striking the camera and metering mechanisms.